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  <name xmlns:md="http://cnx.rice.edu/mdml/0.4" xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/">Discrete-Time Fourier Transform (DTFT)</name>

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      <md:firstname xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/">Richard</md:firstname>
      <md:othername xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/">G.</md:othername>
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      <md:firstname xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/">Richard</md:firstname>
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      <md:firstname xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/">Mariyah</md:firstname>
      
      <md:surname xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/">Poonawala</md:surname>
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      <md:firstname xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/">Prashant</md:firstname>
      
      <md:surname xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/">Singh</md:surname>
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  <md:keywordlist xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/">
    <md:keyword xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/">continuous frequency</md:keyword>
    <md:keyword xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/">discrete time</md:keyword>
    <md:keyword xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/">DTFT</md:keyword>
    <md:keyword xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/">fourier transform</md:keyword>
  </md:keywordlist>

  <md:abstract xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/">Details the discrete-time fourier transform.</md:abstract>
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    <equation xmlns:md="http://cnx.rice.edu/mdml/0.4" xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/" id="eqn1">
      <name xmlns:md="http://cnx.rice.edu/mdml/0.4" xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/">Discrete-Time Fourier Transform</name>
      <m:math>
	<m:apply>
	  <m:eq/>
	  <m:apply>
	    <m:ci type="fn">X</m:ci>
	    <m:ci>ω</m:ci>
	  </m:apply>
	  <m:apply>
	    <m:sum/>
	    <m:bvar>
	      <m:ci>n</m:ci>
	    </m:bvar>
	    <m:lowlimit>
	      <m:apply>
		<m:minus/>
		<m:infinity/>
	      </m:apply>
	    </m:lowlimit>
	    <m:uplimit>
	      <m:infinity/>
	    </m:uplimit>
	    <m:apply>
	      <m:times/>
	      <m:apply>
		<m:ci type="fn">x</m:ci>
		<m:ci>n</m:ci>
	      </m:apply>
	      <m:apply>
		<m:exp/>
		<m:apply>
		  <m:minus/>
		  <m:apply>
		    <m:times/>
		    <m:imaginaryi/>
		    <m:ci>ω</m:ci>
		    <m:ci>n</m:ci>
		  </m:apply>
		</m:apply>
	      </m:apply>
	    </m:apply>
	  </m:apply>
	</m:apply>
      </m:math>
    </equation>

    <equation xmlns:md="http://cnx.rice.edu/mdml/0.4" xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/" id="eqn2">
      <name xmlns:md="http://cnx.rice.edu/mdml/0.4" xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/">Inverse Discrete-Time Fourier Transform</name>
      <m:math>
	<m:apply>
	  <m:eq/>
	  <m:apply>
	    <m:ci type="fn">x</m:ci>
	    <m:ci>n</m:ci>
	  </m:apply>
	  <m:apply>
	    <m:times/>
	    <m:apply>
	      <m:divide/>
	      <m:cn>1</m:cn>
	      <m:apply>
		<m:times/>
		<m:cn>2</m:cn>
		<m:pi/>
	      </m:apply>
	    </m:apply>
	    <m:apply>
	      <m:int/>
	      <m:bvar>
		<m:ci>ω</m:ci>
	      </m:bvar>
	      <m:lowlimit>
		<m:cn>0</m:cn>
	      </m:lowlimit>
	      <m:uplimit>
		<m:apply>
		  <m:times/>
		  <m:cn>2</m:cn>
		  <m:pi/>
		</m:apply>
	      </m:uplimit>
	      <m:apply>
		<m:times/>
		<m:apply>
		  <m:ci type="fn">X</m:ci>
		  <m:ci>ω</m:ci>
		</m:apply>
		<m:apply>
		  <m:exp/>
		  <m:apply>
		    <m:times/>
		    <m:imaginaryi/>
		    <m:ci>ω</m:ci>
		    <m:ci>n</m:ci>
		  </m:apply>
		</m:apply>
	      </m:apply>
	    </m:apply>
	  </m:apply>
	</m:apply>
      </m:math>
    </equation>

    <section xmlns:md="http://cnx.rice.edu/mdml/0.4" xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/" id="sect1">
      <name xmlns:md="http://cnx.rice.edu/mdml/0.4" xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/">Relevant Spaces</name>
      <para xmlns:md="http://cnx.rice.edu/mdml/0.4" xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/" id="para1">
	The <cnxn xmlns:md="http://cnx.rice.edu/mdml/0.4" xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/" strength="7" document="m10247"> Discrete-Time Fourier 
        Transform </cnxn>maps infinite-length,
	discrete-time signals in
	<m:math>
	  <m:ci><m:msup>
	      <m:mi>l</m:mi>
	      <m:mn>2</m:mn>
	    </m:msup></m:ci>
	</m:math>
	to finite-length (or 
	<m:math>
	      <m:apply>
		<m:times/>
		<m:cn>2</m:cn>
		<m:pi/>
	      </m:apply>
	</m:math>-periodic), continuous-frequency
	signals in
	<m:math>
	  <m:ci><m:msup>
	      <m:mi>L</m:mi>
	      <m:mn>2</m:mn>
	    </m:msup></m:ci>
	</m:math>.
      </para>

      <figure xmlns:md="http://cnx.rice.edu/mdml/0.4" xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/" id="fig1">
	<media xmlns:md="http://cnx.rice.edu/mdml/0.4" xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/" type="image/png" src="DTFT1.png"/>
	<caption xmlns:md="http://cnx.rice.edu/mdml/0.4" xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/">
	  Mapping 
	  <m:math>
	    <m:apply>
	      <m:ci type="fn"><m:msup>
		  <m:mi>l</m:mi>
		  <m:mn>2</m:mn>
		</m:msup></m:ci>
	      <m:integers/>
	    </m:apply>
	  </m:math>
	  in the time domain to
	  <m:math>
	    <m:apply>
	      <m:ci type="fn"><m:msup>
		  <m:mi>L</m:mi>
		  <m:mn>2</m:mn>
		</m:msup></m:ci>
	      <m:interval closure="closed-open">
		<m:cn>0</m:cn>
		<m:apply>
		  <m:times/>
		  <m:cn>2</m:cn>
		  <m:pi/>
		</m:apply>
	      </m:interval>
	    </m:apply>
	  </m:math>
	  in the frequency domain.
	</caption>
      </figure>
    </section>

  </content>
</document>
